SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7369ba163f061ad1f794fa6157812c2efa9c5dc68cbca6faf2752591ac9e117' 
  AND token = 'PJ1e99mqasq+0pPN/X6UZRS5umWEjRZHW0QGXYbuiyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}